随钻地质导向的理论与实践探讨

Discussion on the Theory and Practice of Geosteering While Drilling

摘要: 近年来，随钻地质导向技术发展迅速，经历了多个发展阶段。针对目前随钻地质导向与油藏综合研究技术思路不一致的情况，提出了随钻地质层次建模与导向的思想，并利用研究区实例进行了详细说明。研究表明：①随钻地质导向与三维地质建模技术关系密切，把成熟的三维地质建模技术引入到地质导向中来，是实现智能化、高效化导向的发展方向；②水平井层次导向是地质导向理论发展的方向，多层次的导向对应的是地质多层次的科学综合研究成果；几何导向与层次导向在地层-构造格架层次相似度比较高，然而在储层沉积相(构型)、储层参数及流体分布等方面多级次的非均质性几何导向则几乎没有考虑，导致了目前对“甜点”的识别精度不够；③实例显示了地质多层次建模在水平井导向中优势明显，建立了格架模型、岩相模型及录井参数模型，通过实钻数据与预测模型的对比，给出了最优化的轨迹。上述研究为高效钻遇油气层、可视化钻井监测提供了参考依据。

Abstract: In recent years, the geosteering while drilling (GWD) technology has gone through rapid devel-opment of several stages. In light of the inconsistency between the idea of geosteering while drilling and comprehensive reservoir research, the idea of hierarchical modeling and geosteering while drilling was put forward, and it was explained with an example in the study area. The results show that ① the geosteering while drilling is closely related to the three-dimensional geological modeling technology, and it is the developmental direction of intelligent and efficient orientation to introduce the mature three-dimensional geological modeling technology into geosteering; ② the horizontal well hierarchical geosteering is the developmental direction of geosteering theory, and multi-level geosteering corresponds to comprehensive multi-level geological research results; the similarity between geometric orientation and hierarchical orientation is relatively high in stratigraphic-tectonic framework level, but the multi-level of reservoir heterogeneity geometrical guidance, such as reservoir sedimentary facies (reservoir architecture), reservoir parameters and fluid distribution, is not considered almost, which leads to the lower precision in identification of “sweet spot”; ③ the example shows that the geologic multi-level modeling has obvious advantages in geosteering of horizontal well. Framework model, lithofacies model and logging parameter model are established. By comparing the real drilling data with the forecasting model, optimized trajectory can be obtained. This provides a reference for efficient drilling of oil and gas layers and visual drilling monitoring.